Showing papers on "Thermal mass flow meter published in 1967"

Modified turbine mass flow meter

Abstract: 1,211,931. Measuring mass flow-rate electrically. ESSO RESEARCH & ENG. CO. Jan.17, 1968 [Jan.30, 1967], No. 2564/68. Heading G1N. The mass flow-rate of a gas in pipe-line 11 Fig. 1 is determined by measuring the frequency of rotation of a turbine 15 in a tubular bore choke 12 inserted in the pipe-line and dividing this into the differential pressure across the ends of the choke. As shown, rotation of the turbine is sensed by transducer 25 producing a pulse train whose frequency is proportional to the velocity of the gas, and the difference in gas pressure at the ends of the choke is determined by transducer 21 whose output is divided at 28 by the analogue equivalent of the pulse frequency, the quotient being indicative of the mass flow-rate and is shown in digital form at 33. Straightening vanes 17, 18, 34 are provided in the choke and the pipe-line.

Use of Bagnold's velocity meter in laboratory density current measurements

Abstract: A modified version of Bagnold's velocity meter, suitable for determining the mean velocity at a point in a salt water laboratory density current, is described. The dynamic head detected by a small bore Pitot nozzle is balanced by the dynamic head of an opposing jet of fresh water. The position of the interface between the salt water in the nozzle and the opposing fresh water flow is detected by a simple conductivity meter. The meter is calibrated by immersing it in a salt water flow of known velocity and by adjusting the opposing flow until the interface reaches a known position. The effect on meter calibration of varying critical meter dimensions, opposing flow temperature, salt water density and horizontal yaw is shown. The useful range of the meter is 0.03-0.5 ft sec-1 and the accuracy is to better than 5%.

Paper 8: Measurement of Pulsating Air Flow by Means of a Bi-Directional Orifice Meter

Abstract: This paper discusses experiments carried out to investigate the errors involved when applying the steady flow methods of air measurement to air flows which are pulsating at frequencies between 30 and 130 cycles per second (Hz).The mass flow measurements for steady and pulsating flow conditions are obtained by using four different sizes of bi-directional square-edged orifice plates with D and D/2 pressure tappings and a comparison of discharge coefficients for the subsonic flow of air in a 1-in diameter pipe, and the measurements cover a range of mass flows up to 0·03 lb/s.Attempts are made to determine suitable correction factors and thus establish a commercially satisfactory means of air flow measurement from the delivery side of a two-lobed, Roots-type positive displacement blower. The following effects are discussed: (1) the significance of the non-dimensional parameters involved, and (2) the effect of pulse shape.